Field
Implementations of the present disclosure generally relate to a susceptor for use in a thermal process chamber.
Description of the Related Art
Semiconductor substrates are processed for a wide variety of applications, including the fabrication of integrated devices and microdevices. During processing, the substrate is positioned on a susceptor within a process chamber. Susceptors often have platter or dish-shaped upper surfaces that are used to support the substrate from below around the edges of the substrate while leaving a small gap between the remaining lower surface of the substrate and the upper surface of the susceptor. The susceptor is supported by a support shaft, which is rotatable about a central axis. Precise control over a heating source, such as a plurality of heating lamps disposed below the susceptor, allows a susceptor to be heated within very strict tolerances. The heated susceptor can then transfer heat to the substrate, primarily by radiation emitted by the susceptor.
Despite the precise control of heating the susceptor, it has been observed that the susceptor may cause temperature non-uniformity across the substrate due to non-uniform heat convection or conduction heat losses from regions of the substrate in contact with the susceptor and substrate regions not in contact with the susceptor. Temperature non-uniformities persist across the upper surface of the substrate often reducing the quality of the layers deposited on the substrate. Undesirable temperature profiles have been observed near the edges of the substrate as well as over areas closer to the center of the substrate. Therefore, a need exists for an improved susceptor for supporting and heating substrates in semiconductor processing.